A guide to the science behind Interstellar

Interstellar is inspired by many of the best sci-fi films and books, most notably Stanley Kubrick's adaptation of the Arthur C. Clarke novel,2001: A Space Odyssey, which the director Christopher Nolan first saw, aged seven. Like 2001, Interstellar has a strong foundation in real science. Director Christopher Nolan worked closely with people like Kip Thorne, a heavyweight in the field of theoretical physics, to integrate concepts like relativity, event horizons and even complex rocket equations into the film's plot. We dusted off our A Level textbooks to put together this spoiler-free guide to the science in Interstellar.

Black hole

One of the most prominent scientific features of

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Interstellar is the 'Gargantua' black hole. It's overwhelmingly beautiful to look at, and it's a giant pain in the arse for the film's characters. To bring the black hole to life the CGI team modelled a black hole using information from academic journals - covered in complex equations - provided by the film's scientific advisor, Kip Thorne. According to American Wired's feature on the process, it's possibly one of the most scientifically accurate black holes ever created in a sci-fi film.

What is it? A black hole is a gravitational mass which is so large that not even light can escape from it. They're like the plug holes of the universe with a 'singularity' at the centre (instead of the plumbing) where gravity and space are infinite. They're formed when very large stars collapse at the end of their lives. There's a giant one at the centre of our galaxy, which has a mass equivalent to four million suns.

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Accretion disk

The swirling yellow ring of super-hot gases circling Gargantua is called an accretion disk. It's one of the most stunning sights in the film.

What is it? Black holes attract lots of matter, which can even include gas from other suns. As the matter orbits the black hole (before it falls in) it gets heated up. Accretion disks around black holes are among the brightest and hottest objects in our universe and are also called 'Quasars'. Some of these are so hot and bright they can outshine entire galaxies.

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Event horizon

Top tip: don't go near one of these, unless you happen to be a fictional character in a sci-fi movie (and even then, be careful).

We dare not say any more.

What is it? The event horizon is point on the perimeter of a black hole where the gravity becomes so strong that not even light can escape. Once you pass a black hole's event horizon, there's no way back (or is there?). According to Stephen Hawking, with larger black holes it's possible to pass over the event horizon without noticing. Smaller ones will probably tear you apart before you reach the horizon. This is all very relevant information for the characters of Interstellar.

Einstein-Rosen bridge (aka a wormhole)

A sci-fi screenwriter's favourite invention, the wormhole is one of the most mysterious objects in Interstellar's universe, and you get to go inside too. If you're watching on an IMAX screen you'll really feel like you're following the characters down the rabbit hole.

What is it? A wormhole is a hypothetical concept which might enable a significantly advanced civilisation to transport things instantaneously between two points in the universe. At the moment we have no observable evidence that wormholes actually exist, but many physicists have explored the concept using equations in general relativity. Kip Thorne investigated the idea that you could use wormholes to travel back and forth between two different points within space and time in a 1988 paper. His thoughts about wormholes and whether or not it's possible to travel back in time using wormholes are raised in

Interstellar.

Photography by PA Photos

Relativity and time dilation

We mentioned how the black hole Gargantua is a major pain in the arse for our characters. That's mainly because of the time dilation effects caused by super-massive black holes.

What is it? Thanks to Einstein we know that space and time are interwoven: your speed, and your distance in relation to gravitational masses, affect how relatively fast you travel through time. For example, clocks on GPS satellites orbiting the earth at a great distance from the planet tick slightly faster than clocks ticking on earth. The gravitational mass of a black hole is so large that if you travel close to it your watch would appear to slow (or even stop) to people watching from afar.

Photography by Rex Features

Tsiolkovsky Rocket equation

If the earth becomes uninhabitable at some point in the future (as it does in Interstellar), we might have to leave. Unfortunately putting heavy things into space - like, say, every human being on the planet - requires a lot of fuel. The fact that a significant part of the plot pivots around an equation like this one is another sign that Interstellar is not your typical blockbuster.

What is it?

According to the Tsiolkovsky Rocket equation, "a one-ton craft needs 20 to 50 tonnes of fuel" to escape earth's gravity, and since the whole of humanity weighs about 400 million tonnes, launching everyone into space would require taking tens of trillions of tonnes of fuel. That's not even counting all the stuff we'd want to bring with us. Thanks a lot, physics.

Photography by Lightfarm Studios

O'Neill cylinder

We can't really talk about this without revealing the plot.

You'll just have to watch the film (and you really should). The fact that we're even mentioning it is bordering on a spoiler...

Put a giant cylinder in space with a radius of about ten miles, and spin it at a rate of about 40 times an hour, and you'd have an artificial gravity equal to that on earth. Now all you've got to do is build a spacecraft the diameter of the M25.